Welding apparatus



June 22, 1943. F. c. OWEN 2,322,709

WELDING APPARATUS Filed Jan. 13, 1939 ficiem'c/f C 0144970 Patented Jun 22, 1943 I UNITED STATES PATENT OFFICE WELDING APPARATUS Frederick 0. Owen, Fayettevllie, N. 0. Application January 13, 1939, Serial No. 250,832 1 Claim. (01. 219-8) The object oi. the invention is to provide a The auxiliary transformer B is similar to the welding apparatus susceptible of all the funcmain transformerA andincludesa core I! on the tions of the welding transformer disclosed in ap center leg 33 of which are wound the primary 34 piicatlon No. 79,367, flied May 12, 1936 by the and e ary It. one rminal of the primary applicant herein and wlththe same efliciency; being connected to the terminal of the inductto provide a welding apparatus in-which the parts ance coil 2i remote from the terminal II and the may be housed in a metallic case without the remaining terminalbeingconnectedtoone of the likelihood of heating the latter from eddy cur welding leads 36 of which the other welding lead rents produced by stray magnetic fields; and to is connected to the secondary II of the main provide apparatus of the kind indicated which is 10 transformer A.

reduced to its most effective form for the varied In the welding operation, one of the welding character of work encountered in welding operaleads is connected to th work 31 and the other tions of all kinds with various metals. to the electrode ll through the electrode holder With this object in view, the invention con- 39.-

slsts in a construction and combination of parts The secondary II oi the auxiliary transformer of which a preferred embodiment is illustrated in is connected to a capacitance ll in the form of the accompanying drawing but to which the ina bank or condenser The auxiliary transformvention is not to be restricted. Practical applier B is of the step-up ype which makes possible cation may dictate certain change or alterations the use of capacitors at the most economical voltand the right is claimed to make any which fall age and at the same time without danger to the within the spirit 01' the invention. operator. v

The figure is a diagrammatic view of improved The welding current for diil'erent kinds of apparatus constituting th invention. work can be varied by the proper use of the The welding apparatus disclosed in the drawmovable contacts II and II which may be incoring comprises a main transformer A. an auxiliary 2' porated. ii desired-in p chan ing switches. transformer B with a reactor included in the con With the improved apparatus the arc is nections between the smooth, easy to strike and maintain and is prac- The main transformer A embodies a core Ill of tically unaffected by wet work or moisture. The

ll of which the primary winding i2 and secoperation and, during idling periods, the chargondary winding it are wound, the leads of the ing currentispractically nil.

primary winding being brought to a control Oscillograph records made of the apparatus switch It by which the main transformer may be show the current wave to be a sine wave while connected to a supply line. the voltage wave is unusually iiat and smooth for The secondary winding I3 is tapped, as india welding arc with very few and comparatively cated at i5, i6 and H, in order to provide for small peaks at points indicating the instants of varying the secondary voltage, said taps being seignition of the arc. The oscillograms also indilectively engageable with a movable contact i8 cate that there are present voltage of very high connected by a conductor is with a similar confrequencies that are harmonics of the frequencies tact 20 by means 01' which the effective inductof the exciting voltage. These high frequency ance of the reactance coil 2| maybe varied. voltages make for smoothness of the arc and ease The reactance coil 2| is carried on the center of operation of the welder. leg 22 of a core 23, likewise or the closed mag- While the apparatus herein disclosed obtains netic circuit type but the center leg is split transunanticipated or unexpected results with the versely, as indicated at 24, to provide an air gap easy-to-weld metals, such as wrought iron and which, however, is bridged by the inductance steel, its outstanding accomplishment is the re coil 2|, the latter being completely wound around suits obtained on such metal as cast iron. brass.- the leg 22 and the air gap 24 being formed at the aluminum and stainless steel. Good sound malongitudinal center of the leg. The inductance chineable welds can be made with cast iron with coil 2| is tapped, as indicated at 26, 21, 28, 29, 30 less preparation and trouble than heretofore exand 3 I, and the movable contact 20 i engageable perienced and the amount of preheating can also with any one or these contacts or with the terbe greatly reduced. Yellow brass or bras with minal contact 25, so that any desired increment a high zinc content can be welded efiectively with of inductance or the entire inductance may be a metallic arc, as can also aluminum, and all includedincircuit. 66 this with a minimum of prehe And the some results can be accomplished with stainless ondary windinis thereon, a. capacitance connectlteel. ed acres; the secondary oi the auxiliary trans- I'ho invention having been described, what is iormer, and a reactor having a core providin: a chimed as new anduleiulis' closed magnetic circuit interrupted with an air Welding apparatus comprising a. main trans- 5 up and a. windin: mounted on the core and former having a core providing a closed magnetic 'bridging the air gap, the secondary or the main circuit and closely coupled primary and secondtransformer, the winding of the reactor and the dry windings thereon. an auxiliary transformer primary of the auxiliary transformer being seri having a core likewise providing a closed magally connected and in series with welding leads. netic circuit and closely coupled primary and sec- 10 FREDERICK C. OWEN. 

